First visit to W.Va. mine aborted because of gas

CHARLESTON, W.Va. 
Dangerous gases forced investigators to retreat Wednesday after they ventured for the first time into a West Virginia coal mine where 29 men died in a powerful explosion.

Reconnaissance teams that included government and Massey Energy representatives made it about about 1,000 feet into the company's Upper Big Branch mine before turning back Wednesday morning, federal Mine Safety and Health Administration spokeswoman Amy Louviere said. The two teams left after about an hour because handheld meters registered potentially elevated levels of toxic carbon monoxide and explosive methane gas.

"Right now we are just trying to determine the validity of the earlier handheld detector reading," West Virginia mine safety chief Ron Wooten said through a spokeswoman.

Investigators are anxious to get inside the mine to look for clues to what caused the April 5 explosion - the nation's worst coal mining disaster in 40 years. No one had been inside the mine since rescuers recovered the last of the dead in April.

The teams hope re-enter the mine, possibly later Wednesday, after checking instruments and testing air samples taken underground, West Virginia mine agency spokeswoman Leslie Fitzwater said.

High levels of carbon monoxide can indicate the presence of a mine fire, but Louviere said the source of the gas is not known.

The aim of the initial visit is to map the mine and collect air samples. A borehole must be drilled to increase ventilation before investigators can attempt to make it all the way to the area where the men killed in the blast were working. Louviere expects the borehole to be finished by Thursday.